1. Field of the Invention
The present invention relates to methods and systems for testing data signal transceivers, and in particular, to methods and systems for testing multiple data signal transceivers with minimal test equipment.
2. Related Art
As electronic devices and systems have become more complex, testing their performance for compliance with specifications has become more complex and costly. Indeed, while such devices and systems become increasingly integrated and manufacturing costs decrease, costs for testing often increase, particularly when testing such products in high volumes. While the time needed to properly test such products is important, test equipment costs (including acquisition, operation, training and maintenance) must also be considered since such costs are often significant. Relevant to this consideration is test equipment utilization, i.e., more complete use of test equipment in terms of both capabilities and time maximize cost efficiency.
Typically, measurements performed as part of an overall test sequence can often be separated with each measurement then optimized for performance in the least amount of time. For example, a measurement of the transmitter for a radio frequency (RF) transceiver will typically include a command to control the device under test (DUT), followed by capturing and digitizing the resulting transmitted signal, following which, in turn, the digitized signal is analyzed. Often, the digitized signal is moved into a different area of memory so as to free up that portion of memory for use in storing newly captured and digitized data, thereby enabling the capture and digitizing of a subsequent signal while the previous signal is analyzed. Such movement of the captured and digitized data can occur after the capture and digitizing is completed, or it can occur while capturing and digitizing is going on by use of more complex memory structures, such as dual port or dual bank memory.
In the case of simple data verification, it is relatively simple to begin capturing and digitizing new signal data while the previous signal data is being analyzed, although the necessary control software can be more complex due to the need for new commands to capture new signal data before completion of the previous data processing. In the case of data calibration, it can be more difficult as program progress and decisions often depend upon the previous results to determine the next step.
In high volume manufacturing tests, multiple manufacturing lines often run in parallel with each manufacturing station to accommodate more than one DUT, thereby minimizing required testing area (e.g., floor space). For example, this can be done by stacking test equipment such that two testers are used to test four DUTs as part of one test setup. If handling time is comparable to testing time, “ping-pong” testing can be performed by which one DUT is loaded while the other DUT is tested, thereby reducing the amount of test equipment by half and improving test equipment utilization. However, with test times generally being longer compared to the handling time, benefits of such “ping-pong” testing tend to be minimal.
Another cost reduction technique has been to integrate multiple test instruments as a single unit. This can often reduce the cost of the test equipment, at least somewhat, particularly as long as various portions of the individual instruments can be operated independently of each other, thereby increasing test instrument utilization and decreasing the space required for such test equipment.